This invention relates generally to gas turbine engines, and more particularly to combustors of such engines.
A gas turbine engine includes a compressor that provides pressurized air to a combustor wherein the air is mixed with fuel and burned for generating hot combustion gases. These gases flow downstream to one or more turbines that extract energy therefrom to power the compressor and provide useful work such as powering an aircraft in flight. Annular combustors used in aircraft engines typically include inner and outer combustion liners joined at their upstream ends to a dome assembly or simply a “dome.” The dome assembly includes an annular dome plate and a plurality of circumferentially spaced mixer assemblies mounted therein for introducing the fuel/air mixture to the combustion chamber. Each mixer assembly has a deflector extending downstream therefrom for preventing excessive dispersion of the fuel/air mixture and shielding the dome plate from the hot combustion gases of the combustion chamber. A fuel injector stem extends into in each mixer assembly.
In one known dome configuration, the deflectors are rigidly mounted to the dome plate (for example by brazing), while the mixers are loosely mounted to the dome plate so that some relative motion is possible. Until the fuel injector stems are installed, the mixers can become dislodged from their intended positions. Prior art designs address this problem by using separate bolted-on components such as retention tabs to retain the swirlers. This drives up the complexity and time required to assemble the combustor, and can increase thermal stresses in the combustor during operation because of the presence of the bolted joints.
Accordingly, there is a need for a combustor dome assembly that is simple to assemble, which reliably retains the mixers and deflectors.